The Sydney Morning Herald said 4 Squadron of the elite Special Air Service (SAS) had mounted dozens of clandestine operations in places such as Zimbabwe, Nigeria and Kenya in a role normally carried out by spies.

Citing a government source, it said the missions by the previously unknown squadron were believed to involve terrorism intelligence gathering amid concerns about the threat posed by the Islamist al-Shebab militia.

They are also aimed at developing rescue strategies for evacuating trapped Australian civilians while assessing African border controls and exploring landing sites for possible military interventions.